dup2              706 include/ruby/win32.h #undef dup2
dup2              707 include/ruby/win32.h #define dup2(o, n)		rb_w32_dup2(o, n)
dup2               27 missing/dup2.c dup2(int fd1, int fd2)
dup2              100 win32/win32.c  #undef dup2